Envelope or the like



Aor the like;

these operations must be reversed. Moreover,

Patented Sept. 7, 1943 UNITED STATES PATENT OFFICE ENVELOPE B THE LIKE Albert I. Kegan, Chicago, Ill. Application April 6, 1939, Serial No. 266,321

17 Claims.

The present application is in part a continuation of my copending application Serial No. 740,885, filed August 22, 1934, from which matured Patent No. 2,168,873, granted August 8, 1939.

The present invention relates to containers, such as envelopes, mail wrappers, and the like, and more particularly to envelopes which are adapted to be repeatedly sealed, opened, and resealed, for purposes of postal inspection, for example, but which also may be permanently sealed for mailing first class matter if desired.

Envelopes capable of being repeatedly opened and closed have heretofore been provided with some type of metallic fastener and eyelet or with a string and button, to retain the ap in its closed `relationship to the body of the container. 'Ihese fastening devices all have certain disdavantages, both as regards the cost of manufacture, and also as regards their inconvenience in use. 'I'hey must be attached to the otherwise complete envelopes by a series of separate operations ordinarily requiring the use of riveting machinery or other special equipment, so that the attachment of these devices not only involves a considerable expense but also materially slows down the rate of production. In order to close envelopes embodying previous constructions, theuser is obliged to perform' various preliminary operations such as raising the clasps, followed by the motions required to effect closure, v'such as inserting the clasps in a small opening in the flap and attening them out, or winding a string about a button,

and in order to open the envelopes such prior containers do not close in-` suchl a manner as to prevent the adventitious entrance of foreign materials such as dust and-the like.-

One of the objects of the present invention-iste provide a container for mailing and other purl poses which is inexpensive to manufacture, and

which is simple and easy to open, for example, for purposes of postal inspection.

. which may be permanently sealed by moistening one of the sealing areas and pressing it upon the other sealing area, said permanent seal being formed even though the sealing areas have previously been used a number of times for drysealing repeat-sealing purposes.

Still another object comprises an envelope provided with a coating capable of repeat-sealing, when dry, to properly prepared surfaces and also capable of permanently sealing, when moistened, to similar surfaces or g to ordinary uncoated surfaces.

Other objects will become apparent as the invention is hereinafter more particularly described.

'I'he foregoing objects may be attained in accordance with the present invention, in which inexpensive fluids or semi-solid compositions that are easy to handle are applied to the appropriate regions of the container and dried to deposit thereon coatings which actually strengthen the fabric, which elect closure by the simple operation of being pressed together, and which permit the opening of the container by the equally simple operation of being pulled apart-said operation being made extremely convenient by the Fig. 1 isa view invertical central section through a container which may be repeatedly .opened and sealed, and illustrates the .envelope in its sealed relationship,

vretained therein. It also illustrates diagrammawith a bulky object tic'ally the forces exerted by said object.

Fig. 2 is a back viewV of an open end of an envelope constructed in accordance with the ,present invention.

fio

Fig.- 3 is aback view of an open end of an envelope for enclosing bulky material and illustrates a modified Another object of the present` invention is to provide containers which may be easily and `quickly opened and thereafter resealed by pressure only, which containers when closed possess sufllcient strength to retain bulky materials such as catalogs or the like without rupture ofthe seal.

Another object is toprovide an entirely new article of manufacture consisting of an envelope whichv may be repeatedly sealedl and unsealed when the coacting 'coatings are pressed together vin a. dry condition, but which nevertheless may be firmly and permanently sealed if preferred by pressing such coatings together after one or both envelope construction in accordance with theinvention.

Fig. 4 is a back view of envelope, the ilap of which is provided with creases disposed yin angular relationship to each other. whereby contact of the adhesive areas may be avoided whendesired.

Fig. 5 is similar to Figs. 1 and 2, and illustrates another method of applying coacting coated surfaces to the envelope. y

Fig. 6 is a side elevation of an open end of an envelope similar to that with the ilap folded to bring the adhesive areas into alignment for sealing.

an open end of an shown in Fig. 5, and

ltrated in Fig. 2 comprises Referring generally to the drawing, the invention is illustrated with reference to containers adapted to enclose material to be carried in the mails at reduced rates of postage, and therefore constructed in such a manner that the containers may be easily, quickly, and repeatedly opened fonpostal inspection and resealed by pressure only, but which may nevertheless be used if desired to seal the contents against inspection so as to constitute first class mail.

Fig, 1 illustrates the basic construction embodying the present invention, and indicates diagrammatically the action of the forces involved. Fig. 1 is a view in vertical central section of a container consisting of a body I and a flap 2, having a book or similar object A loosely enclosed therein. Portions of the flap and body are provided with appropriate sealing lms 3 and 4, as hereinafter more fully described, and are shown engaged to effect closure of the container. When the body of the container is suspended at any point 5, the contents exert a force on the container,`as indicated by the arrow B, said force consisting of a component C perpendicular to the surface of contact of the coatings 3 and 4 and a component D parallel to said surface of contact. The component C is transmitted through the object A and the'body I of the container to the coating 4, and thus serves to press said coating 4 even more securely against coating 3. The component D the object A and the flap 2 to the coating 3, and thus tends to move said coating 3 over coating 4 in the plane of mutual contact. The coatings of the present invention, however, possess a resistance to the tendency toward relative displacement in this direction sufficient to prevent such displacement, from occurring, and the container remains sealed. Since 5 represents any point of suspension whatsoever, it is apparent that all possible stresses due to the movement or weight of the contents of the container can exert, themselves against the closure only in the direction in which the coacting coatings possess the greatest resistance to separation, and then only in such a manner as to increase the effectiveness of the seal by holding the coacting coatings in closer contact. In numerous tests, containers embodying the present invention have been agitated with heavy objects loosely enclosed therein until the contents tore through the fabric of the container, and in every case this treatment failed to separate the coacting coatings.

However, by pulling the tab 6 outwardly from the body of the container, the coating 3 is readily stripped away from its complementary coating 4 (when the latter is dry-sealed to the former, as hereinafter explained) and thus the container may be opened with ease whenever it is desired to do so, after which it may again be effectively sealed by again pressing the flap down against the body of the envelope and thus bringing the complementary coated areas into contact under pressure. I

Figs. 2 to 6, inclusive, illustrate various embodiments of this invention. The article illusan envelope body I having an area 3 of a suitable sealing composition thereon as hereinbelow described, and a ap 2 having thereon a complemental area 4 likewise coated with sealing composition, and having attached thereto a tub 6. This tab provides a means whereby the flap may be grasped and pulled outwardly from the envelope body whenever it is desired to open the envelope, as for is transmitted through the flap in its closed position, the appearance` example, for inspection of its contents by the postal authorities. If desired,v the flap may be lightly scored along the dotted line I in order that the ta-b may be raised easily. Since the dry coatings do not stick to the fingers .or to uncoated portions of the envelope, the tab 6 is preferably coated with the same composition as is applied to the region 4, thus utilizing the strength, toughness and resistance to flexing of these sealing coatings to reinforce the fabric and allow the envelope to be freely opened and resealed without tearing the tab. .If the tab is coated, its complemental area below the region' 3 is left uncoated, so that folding the ap along the usual folding linel does not cause the tab to be fastened to the body of the envelope, since the composition coating does not dry-seal to paper, as stated previously.

In the embodiment illustrated in Fig. 2 the flap is sealed completely to the corners of the envelope, which protects the interior from the adventitious entrance of dirt and the like and which also prevents other envelopes or cards from engaging underneath the flap and tending to loosen 'it during handling or transportation.

Fig. 3 illustrates an embodiment provided with restricted sealing areas 3a and 4a in conjunction with a construction designed to completely enclose bulky objects. In enclosing an object of this type, the flap folds on the lines 8 and 9 so that the region therebetween'covers the top of the contents, and-part of the region 4A makes contact with all of the region 3A in order toseal then being somewhat similar to that illustrated in Fig. 1. The portion 6 serves as a tab for opening purposes and is preferably coated with the sealing composition in order to be thereby strengthened. When the envelope is used to enclose a somewhat smaller object, the flap may be folded on only one of the lines 8 or 9 and part of the region 4A will nevertheless make contact with all of the region 3A and thus close the container.

Fig. 4 is somewhat similar to Fig. 3 except that the envelope is provided with a plurality of folds or scored lines placed in angular relationship to each other, whereby the flap may be folded on the line 9A to maintain the restricted adhesive region 3A out of contact with its complementary adhesive region 4A during storage and whereby the flapmay be folded on the line 8A to bring the adhesive regions into alignment for sealing purposes. When the flap is folded on the line 9A, the adhesive region 4A takes the position indicated at 4B.

In some cases it is desired to apply sealing means to envelopes, the flaps of which either may or may not already have a coating of the ordinary wet-sealing adhesive of the prior art, and for this purpose the embodiment illustrated in Figs. 5 and 6 is provided with small tabs or strips II which may be of any suitable fabric, preferably paper, and which are provided with sealing coatings I2. These strips may if desired have a water-soluble adhesive on one side and sealing composition of the present invention on the other, and they may be glued to the envelopes as illustrated, and when the flap is folded the strips may be sealed together by pressure. These strips may be provided with composition having characteristics allowing them to be readily opened and resealed. The strips preferably extend somewhat beyond the coated region, whereby the end may be used as a tab for opening the sealed envelope. When the envelope is folded, the coated areas arebrought into alignp ment in the manner illustratedin Fig. 6, whereby they may be easily secured together by pressure.

In Fig. 6 the strip attached to the envelope flap 2 is shown as extending beyond the coated region a suiicient distance to permit the strip to be folded inwardly at I4, -as shown loy dotted lines, so that the uncoated portion may lie between the coated regions and prevent themfrom coming in contact'l during storage. When the flap is raised and the strip thereon is unfolded, the

coated regions may be brought into contact.

` The compositions to be used for coatingthe sealing areas of the present invention preferably comprise an aqueous dispersion of rubber, desirably inthe form of rubber latex, in intimate admixture with water-soluble adhesives such as glue, casein, gelatin, dextrin, or the like. The composition may contain only one of the adhesives, or several of them may be used in the same formula. These compositions generally have a rubber content exceeding of the total weight of the coating as applied to the envelope. The rubber content of these compositions generally exceeds 50% of the total solids content thereof.

.By incorporating rubber and water-soluble adhesives in intimate intermixture in one compo-y sition, and utilizing this composition in an envelope structure, unique results are obtained. The sealing areas formed from the compositions of the present invention are attached to the `base fabric with great tenacity. They are not tacky or sticky to the touch, nor do they adhere to the fingers, paper, or typewriter platen on contact in the dry condition. 'I'hey are dry-sealing. They are repeat-sealing. After being dry-sealed together, a pull on the tab strips the coatings apart, instead of stripping one of the coatings o the paper, or tearing off the tab. The coatings retain their properties over long periods of time. They do not lose their usefulness after being used once, but on the contrary, the coacting coatings may be sealed together and disengaged hundreds of times. And with the appropriate proportions of rubber and water-soluble adhesive, the container may be sealed permanently by moistening one of the coated areas before pressing them together. lope of the present invention may be wet sealed to form a permanent seal in the manner indicated even after it has been used a large number of times as a repeat-sealing envelope.

Antioxidants such as aldol-alpha-naphylamine, phenyi-beta-naphthylamine, symmetrical di-beta naphthyl paraphenylenediamine, and

Thus, the envemoistened, will adhere to the body of the envelope.

For every 100 parts by weight of rubber solids, the compositions may contain from 1 to 40 parts of glue, or from 6 to 30 parts ofgelatin, or from 10 to 45 parts of casein, or from 10 to 70 parts of dextrin, or mixtures of two or more of the foregoing adhesives within the proportions indicated. Hygroscopic substances such as sugar, glycerol, calcium chloride andthe like may be incorporated in small amounts into the compo-.- sitions, and increase their adhesiveness. The compositions which give the most effective per- 1 manent seals after being moistened contain the added to make i-t alkaline.

higher proportions of water-soluble adhesives.

In ordermore particularly to disclose the nature of the compositions, several examples will now -be more fully described. It should be clearly understood, however, that this is done entirely by way of example, and is not to be construed as a limitation upon the spirit and scope of 'the appended claims. In the following examples rall the proportions are indicated on a weight'basis.

n Example I Rubber solids from latex 100 Age-retarder 1 Gelatin 10 Water As required 4 This composition may be prepared in the following manner:

(l) A 30% dispersion of the age-retarder is made by grinding in a pebble mill 3 parts by Weight of the powdered age-retarder with 7 parts of water containing a small amount, say 0.1% to 3%, of a dispersing agent, such as triethanolamine oleate, Darvan, or the like;

(2) Two parts of this 30% dispersion are gradually mixed with 100 parts of a concentrated natural rubber latex containing solids and preserved with ammonia;

(3) A 10% solution of gelatin is prepared. If the reaction is acid, enoughv ammonia water is The gelatin solution may contain preservatives or antiseptics such as cresol, eucalyptol, or phenylmercuric` nitrate in the customary proportions; I

(4) If the gelatin solution soiidies, it is gently warmed, and 60 parts of the 10% gelatin solution are slowly mixed with stirring into the mixture of latex and age-retarder.

'I'his gives a composition which is a viscous fluid while warm, and a solid gel at room temperature. If a more fluid composition is desired,

. water is added, or the formula isfmade up from the like, may be incorporated into the coating compositions to retard the aging of the rubber therein. Gums, such as karaya or tragacanth may be included to increase the viscosity and pick up of the composition in the iluid'condition. Wetting agents such as Aerosol, Tergitol, or Gardinol may be utilized to increase the penetration of the fluid composition into the fabric of the envelope.

an unconcentrated natural latex.

When this composition is spread on paper, coagulated, and most of the water evaporated, preferably in conjunction with the application of heat, a clear transparent film is obtained tenaciously attached to the fabric and possessing the desired adhesive properties toward similar coatings, combined with the property of not dry-sealing to untreated paper and other materials. Envelopes having corresponding areas coated with this composition are repeat-sealing when dry-sealed, but may be sealed permanently by moistening one or both coatings before pressing them together. The adhesiveness, both for repeat-sealing and for permanent-sealing purposes, of the lms obtained by the use of the above-described composition, or of any of the compositions Within the scope of the p resent invention, may be varied by changing the time or intensity of heating, or by varying the thickness of the film, or both. The films may be increased in thickness by increasing the viscosity of the coating fluid by incorporating therein various gums and the like, as mentioned hereinabove, or by applying the fluid more slowly, or by applying several coats to the same region, or by increasing the solids content of the fluid used, as will be apparent to those skilled in the art.

Example II Rubber solids 100 Age-retarder 2 Zinc oxide -'70 Glue 35-10 Water As required The solids, in the form of aqueous dispersions, are gradually worked into the latex, as described before in detail.

Example III Rubber solids from latex 100 Age-retarder 0.4 Casein .25 Water As required Example IV Rubber solids 100 Age-retarder 1.4 Gelatin 8 Casein 1 .6 Aerosol 0.2 Water As required The various materials are disposed in water and worked into the aqueous dispersion of rubber solids in the manner described in detail hereinabove.

Example V Rubber solids from latex 100 Age-retarder 0.1 Gelatin 10 Karaya 0.4 Water As required The kayara is introduced in the form of a fluid prepared by dissolving 1.8 parts of soda ash in 100 parts of water and slowly working 3 parts of gum karaya into the liquid.

l Example VI Rubber solids from latex 100 Dextrin '70 Sugar 1 Water As required Coatings formed from the formula of Example VI repeat-seal effectively to coatings formed according to Example I. On being moistened, they seal permanently. The coating of Example VI, after being moistened, will adhere to paper and other materials. Thus it is feasible to coat the envelope flap and tab with the composition of Example VI, and to coat the sealing area on the back of the envelope with the composition of Example I. When it is desired to seal the envelope so that it cannot be reopened without tearing it, the coated region on the flap and the tab may both be moistened, whereupon, on closing the envelope, the sealing areas will unite and the tab will also seal to the back of the envelope, so that the means to facilitate disengagement of the coacting coatings is destroyed.

In the foregoing description of the present invention it will be apparent that many variations in detail may be made by those skilled in the art. Thus, for example, vulcanized latex or aqueous dispersions of crude rubber or of reclaim, or mixtures thereof may be substituted for part of the latex speciiled in the formulas hereinabove set forth. In general, however, the vulcanized latex tends to diminish somewhat the readiness with which the coatings adhere, whereas the synthetic dispersions, especially those of crude rubber, increase the tendency toward easy adhesion, but also lessen the strength of the coating. For the foregoing reasons, the rubber solids from latex are preferred.

Many other variations in detail may be made without departing from the spirit of the invention. I therefore intend to be restricted only in 2. A dry-sealing envelope comprising a body portion having a sealing area thereon, a ilap portion having a handle and a sealing area complemental to the sealing area on said body portion, said sealing areas and said handle being coated with non-tacky composition containing rubber, said body portion being uncoated in the region complemental to said handle, said composition strengthening said tab and rendering said envelope repeat sealing.

3. A repeat sealing envelope for retaining relatively heavy objects, comprising a body portion, a nap portion, a handle on said ap portion, a non-tacky coating comprising rubber and water soluble adhesive on said handle to strengthen the same, and similar coatings tenaciously attached to said body portion and said flap portion and arranged to cooperate in keeping said envelope closed without adhering said handle to said body portion, said coatings possessing substantial resistance to separation from each other by the action of objects within said envelope, said envelope being opened by pulling outwardly on said handle.

4. A dry sealing envelope -comprising a body portion having a sealing area thereon, a flap portion having a tab and a sealing area complemental to the sealing area on said body portion, said sealing areas and said tab being coated with a composition comprising rubber and a member selected from the group consisting of gelatin, glue, casein, and dextrin, said body portion being uncoated in the region complemental to said tab, said composition imparting increased mechanical strength to said tab and imparting to said sealing areas the capability repeatedly to adhere to each other after repeatedly being separated from each other.

5. An envelope or the like adapted to repeatseal when dry-sealed and to seal with relative` permanency when Wet-sealed, comprising a body portion, a ilap portion, a tab on' said nap portion, a coating on said tab and on said ilap portion, and a coating on said body portion complemental to the coating on said iiap portion but not to the coating upon said tab, said coatings comprising' a mixture of rubber and moisture-activatable adhesive.

6. A repeat sealing envelope for retaining relatively heavy objects, comprising a body' portion, a iiap portion, a handle on said flap portion, a normally non-tacky composition of rubber and water soluble adhesive on said handle to strengthen the same and to permit said handie to be wet-sealed to said body portion, and similar compositions tenaciously cemented to said body portion and said iap portion and arranged to cooperate in keeping said envelopeclosed, said compositions possessing great resistance to separation from each other by the action of objects within said envelope, said envelope readily being opened by pulling outwardly on said handle.

7. An envelope or the like comprising a body portion, a flap portion, a tab on said ap portion, a coating on said tab and on said flap portion, and a coating on said body portion adapted to make contact with the coating on said ap portion but not with the coating upon said tab, said coatings containing suiilcient rubber repeatedly to seal to each other upon dry contact and containing suilicient moisture-activatable ladhesive to seal permanently to each other upon contact while moist.

8. An envelope or the like comprising a body portion, a ap portion, a tab on said iiap portion, a coating on said tab and on said flap portion, and a coating on said body portion complemental to the coating on said flap portion but not to the coating upon said tab, said coatings comprising an intimate intermixture of a major proportion of rubber and a minor proportion of moisture-activatable adhesive, whereby said envelope is rendered repeat sealing when dry sealed and relatively permanent sealing when wet sealed.

9. An'envelope or the like comprising a body portion, a ilap portion, a tab on said flap portion, a normally non-tacky coating on said tab to reinforce the same, a normally non-tacky coating on said iap portion, and a normally nontacky coating on said body portion arranged to contact the coating on said nap portion but not the coating upon said tab when said ap portion is folded upon said body portion, said coatings y.

comprising a maior proportion of rubber and a minor proportion of moisture-activatable adhesive in intimate intermixture, said envelope being adapted repeatedly ,to be dry-sealed by contact or said coatings with each other and repeatedly to be unsealed by pulling said tab, said coatings sealing together tenaciously after being moistened to resist the opening of said envelope by pulling upon said tab.

10. An envelope comprising a body portion haviing a sealing area thereon, a flap portion having a tab and a sealing area complemental to the sealing area -on said body portion, said sealing areas and said tab being coated with a composition comprising rubber and a member selected from the group consisting of gelatin, glue, casein, and dextrin, said body portion being uncoated in the region complemental to said tab. said composition reenforcing said tab and rendering said envelope repeat sealing when dry sealed and relatively permanent sealing when wet sealed.

11. An envelope or the like adapted to be re-l velope.

peatedly sealed and. unsealed when complemental sealing areas thereon are brought together in dry condition and adapted to seal to resist unsealing when said sealing areas are brought together in moistened condition, comprising a body portion, a ilap portion, a tab on said iiap portion, an intimate intermixture oi' rubber and moisture-activatable adhesive on said tab and on said nap portion, and a rubber coating .arranged on said body portion to cooperate with the composition on said ilap portion but not with the composition on said tab, said tab upon being moistened being capable o! sealing to said body portion. y

12. An envelope or the like provided with complementa] sealing are as to be brought into contact with each other and a handle to facilitate disengaging said sealing areas from each other, said areas and said handle being coated with an intimate intermixture of rubber and moisture-activatable adhesive, whereby said envelope is rendered repeat sealing when dry sealed and relatively permanent sealing when wet, sealed, said handle adhering to the uncoated region ot said body portion only after making contact therewith in moist condition.

13. An envelope or the like provided with complemental sealing areas to be brought into contact with each other and a handle to facilitate disengaging said sealing areas lilrom each other, said areas and said handle being coated with an intimate intermixture of rubber and moisture-aotivatable adhesive whereby said envelope is rendered repeat sealing when dry sealed and relativelypermanent sealing when wet sealed,.the coating upon said handle being sumciently rich in moisture-activatable adhesive to enable said handle to wet`seal tothe uncoated portion of said envelope.

14. An envelope or the like comprising a body portion.' a napportion, a tab on said ilap portion, rubber composition on said tab andon said iap portion, and rubber composition on said body portion arranged to make contact with the composition on said flap portion but not with the composition upon said tab, at least one of said compositions containing suiiicient dextrin to render itkwet-sealing.

15. An envelope or the like provided with complemental sealing areas to be opposed to each other in combination vwith a handle for pulling said areas apart, said areas and said handle being-coated for sealing purposes with a composition comprising rubber solids, a water-soluble adhesive and a hygroscopic agent, said constituents endowing said sealing areas with the capability of being repeatedly sealed and separated when said areas are pressed together in a dry condition, and of being permanently sealed when said areas are pressed together in a moist condition, said handle when moistened being permanently sealed -to the uncoated area of said en- 16. A repeat-sealing venvelope comprising a sealing area on the body portion, a ilap portionV having a corresponding sealing area. and a lifting tab on said ilap portion, said sealing areas and said tab being coated with a composition comprising gelatin and rubber, the area complementa! to said tab being uncoated, said composition imparting to the sealing areas the capability of being repeatedly sealed and separated from each other, and imparting to said lifting tab increased mechanical strength.

17. A repeat-sealing envelope comprising a sealing area. on the body portion, a. ap poring uncoated, said compositions imparting to the tion having' a corresponding sealing area, and a, sealing areas the capability of being repeatedly lifting tab on said nap portion, said sealing areas sealed and separated from each other when said and said tab being coated with a composition areas are pressed together in a dry condition, and comprising rubber and a. member selected from 5 imparting to said lifting tab increased mechanithe group consisting of gelatin. glue, casein, and cal strength.

dex-trin, the area. complemental to said tab 'be- ALBERT I. KEGAN.

CERTIFICATE OF CORRECTION.

Patent No. 2,529,055. september 7, 1914.5.

AIBERT I. KEGAN.

It is hereby certi fied that error appears in the printed specification of the above nunbored patent requiring correction as follows: Page 2, first column, *line 72, for 'tub' read tab; page 1;, first column, line h5, Example IV, for l'di :sposedl read --di spersed; line 5h., Eimnple V, for "kayeraal r'ead. knraya page 5, second column', line 16, claim l2, for "are as read areas" md that the said 'Letters Patent should be readwith this correction therein that'the sane may .conform to the record of the case in the Patent Office.

Signed and sealed this 21st day of December, 1.911,5.

Henry Van Arsdle, (Seal) Acting commissioner of Patents. 

